EVIDENCE FOR ENHANCED REACTIVITY IN THE PHOTOFRAGMENTATION OF THE BRIDGED DINUCLEAR SYSTEM Me2Si5-C5H4Fe(CO)2(η1-CH2C6H5)>2

Article abstract of DOI:10.1016/S0022-328X(00)95261-6

Experimental evidence that the dinuclear complex Me2Si<η⁵-C5H4Fe(CO)2(η¹-CH2C6H5)>2 shows enhanced reactivity over its mononuclear analog η⁵-C5H5Fe(CO)2(η¹-CH2C6H5) in photofragmentation to produce bibenzyl and Fe-Fe bonded product is presented.Information from a series of competition and crossover experiments indicate that two factors are involved in the enhancement: (1) the ability to photochemically produce a 16-electron unsaturated benzyl unit in close proximity to a saturated partner, and (2) the inability of the Fe-Fe bonded species 4 to quench free benzyl radicals in solution.Chemical reaction of Me2Si<η⁵-C5H4Fe(CO)2(η¹-CH2C6H5)>2 with Me3NO produces bibenzyl and establishes that loss of CO is the initial step in the fragmentation reaction.In addition, trapping experiments with 9,10-dihydroanthracene show that bibenzyl is formed from free benzyl radicals; Based on these results an overall mechanism is proposed.